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Updated: Aug 12, 2026

Analysis of Cell Cycle Position in Mammalian Cells
12:19

Analysis of Cell Cycle Position in Mammalian Cells

Published on: January 21, 2012

Polyomavirus large- and small-T relieve middle-T-induced cell cycle arrest in normal fibroblasts

Alain Marti1, Kurt Ballmer-Hofer1

  • 1Institute of Medical Radiobiology at the Paul Scherrer Institute and of the University of Zürich, 5232- Villigen-PSI, Switzerland1.

The Journal of General Virology
|December 2, 1999
PubMed

Insights

Mouse polyomavirus T antigens regulate cell cycle entry. Small-T antigen (ST) cooperates with middle-T (MT) and large-T (LT) to stimulate growth-arrested cells, revealing ST

Area of Science:

  • Cellular biology
  • Virology
  • Molecular oncology

Background:

  • Papovavirus tumor antigens are crucial tools for studying cell growth regulation.
  • Understanding how viral proteins influence the cell cycle is key to cancer research.

Purpose of the Study:

  • To investigate the roles of mouse polyomavirus small-, middle-, and large-T antigens in stimulating cell cycle entry.
  • To elucidate the cooperative interactions among these T antigens in regulating cell proliferation.

Main Methods:

  • Microinjection of REF52 fibroblasts with cDNAs encoding mouse polyomavirus T antigens.
  • Analysis of cell cycle progression (S phase entry) in response to T antigen expression and serum stimulation.

Main Results:

  • Middle-T antigen expression alone inhibited serum-induced cell cycle stimulation.
  • Coexpression of small-T antigen with middle-T antigen released arrested cells into S phase.
  • Simultaneous expression of middle-T and large-T antigens induced cell cycle entry even without serum.

Conclusions:

  • Cooperation among polyomavirus T antigens is essential for T antigen-mediated cell cycle stimulation in growth-arrested cells.
  • Small-T antigen plays a novel role in signaling to mitogenic pathways, cooperating with other T antigens.

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